Gaseous electric discharge device



March 12, 1935. H. EWEST ET AL 1,994,306

GASEOUS ELECTRIC DISCHARGE DEVICE Filed March 5, 1934 mmamrows HansEwest, AHTed RUttenaueT,

ATTORNEY.

Patented Mar. 12, 1935 UNITED STATES 1,994,306 I GASEOUS ELECTRICDISCHARGE DEVICE Hans Ewest, Berlin-Lichterfelde-ost, and AlfredRiittenauer, Berlin-Halens'eaGermany. assignors to General ElectricCompany, a corporation of New York Application March 5. 1934, Serial No.114,190 In Germany March 10, 1933 3 Claims.

The present invention relates to gaseous electric discharge devicesgenerally and more'particularly the invention relates to such devicesthe gaseous atmosphere of which consists of or comprises a vaporizablematerial.

When such devices are operated on direct current the metal vapor travelstoward the cathode and condenses in the cathode parts of the device. Thelight emitting characteristics of the device as well as the operatingcharacteristics thereof are changed disadvantageously by thisphenomenon. The object of the present invention is to provide a directcurrent gaseous electric discharge lamp device having a gaseous fillingconsisting of or comprising a vaporizable material in which the tendencyof the vapor to collect around the cathode portion of the device andcondense thereat is completely overcome. Further objects and advantagesattaching to the device and to its use and operation will be apparent tothose skilled in the art from the following particular description.

In accordance with this object the new and novel lamp device comprises atubular container having a cathode and an anode sealed therein atopposite ends thereof. The anode is a large sheet metal electrodemounted in an electrode chamber having a diameter larger than saidcontainer and the cathode is a thermionic electrode provided with aheater and is mounted in an electrode chamber having a diameter equal toor less than the diameter of said container. During the operation of thedevice the anode chamber radiates a large amount of heat due to thelarge surface thereof and is at a low tem perature while the cathodechamber is at a temperature equal to or higher than the container due tothe heat radiated by the cathode and the small heat radiating surface ofsaid cathode chamber. The metal vapor in a gaseous discharge lamp deviceof this structure does not collect and condense in the cathode chamberand the vaporizable material is in vaporous condition in the dischargepath during the operation of the device. It is to advantage if thesupply of the vaporizable material located in the interior of the anodeand a small glass tube having a quantity of vaporizable material thereinand opening into the interior of the anode is useful for this purpose. Acorrugated surface on the anode chamber to provide a greater heatradiating surface is also advantageous. v

In the drawing accompanying and forming part of this specification anembodiment of the invention is shown in front elevati'oh al, partlysectional view.

Referring to the drawing the new and novel gaseous electric dischargedevice comprises a tubular container 1 having an anode 3 and a 5 cathode9 sealed into opposite ends thereof. Said container 1 has a gaseousatmosphere therein comprising a starting gas, such as argon and avaporizable material, such as sodium. Said anode 3 is a large, hollow,sheet metal 10 electrode and is mounted on a current lead 4 sealed intothe chamber 2 at one end of said container 1.- Said anode 3 has aplurality of openings 7 therein on the side thereof facing away from thedischarge path. A glass tube 5 15' fused to the projecting part 6 of thechamber 2 extends and opens into the interior of said anode 3. Aquantity of vaporizable material, such as sodium, is located in saidtube 5. Said cathode 9 consists of a curved rod consisting of 20 asintered, pressed mixture of high melting point. metal, such astungsten, and electron emitting material, such as barium oxide, thecomposition of the rod being such as to make it substantially anon-conductor of electricity 2:; when it is unheated. A heating coil,such as a tungsten filament, is wrapped around said rod. The ends ofsaid coil are attached to current leads 10 and 11 sealed into thecathode chamber 8 of said container 1.

The cathode chamber 8 is of smaller diameter than the part of saidcontainer 1 surrounding the discharge path between said electrodes 3 and9. The anode chamber 2 of said container 1 is of larger diameter thanthe part 35 of said container 1 surrounding said discharge path. Theanode chamber 2, due to the larger surface thereof, radiates heat morefreely than the cathode chamber 8 and is at a lower temperature thansaid chamber 8 during the oper- 40 ation of the lamp device. The cathodechamber 8, due to the smaller heat radiating surface thereof and theheat radiated by said cathode 9, is at a temperature equal to or greaterthan the temperature of that part of the 45 container 1 surrounding thedischarge path between said electrodes 3 and 9.

The metal vapor in a gaseous discharge lamp having the above describedstructure does not collect and condense in the cathode chamber 50 8during the operation of the device. The vapor in the device is thusmaintained in vaporous condition in the discharge path which increasesthe efliciency of the lamp device.

While we have shown and described and have 66 pounds.

pointed out in the annexed claims certain novel features of theinvention, it will be understood that various omissions, substitutionsand changes in the forms and details of the device illustrated and inits use and operation may be made by those skilled in the artwithoutdeparting from the broad spirit and scope of the invention, forexample, the chamber 2 has corrugated walls to increase the heatradiating surface thereof, when desired and the electrode comprises arod consisting of a mixture of electron emitting materials or their com-What we claim as new and desire. to secure by Letters Patent of theUnited States is:-

l. A gaseous electric discharge device comprising a container, a gaseousatmosphere therein comprising a metal vapor, electrodes sealed thereinone of which is a thermionic cathode and another of which is an anodehaving a large surface, electrode chambers for said electrodes, thechamber in which said anode is mounted having a larger diameter thansaid container, the chamber in which said cathode is mounted having asmaller diameter than said container. a

2. A gaseous electric discharge device comprising a container, a gaseousatmosphere therein comprising a metal vapor, electrodes sealed thereinone of which is a thermionic cathode and another of which is an anodehaving a large surface, electrode chambers for said electrodes, thechamber in which said anode is mounted having a larger diameter thansaid container, the chamber in which said cathode is mounted having 'asmaller diameter than said container, said anode being hollow, one wallthereof being perforated and. a hollow tube projecting and openingintothe interior of said anode, said tube having a quantity of vaporizablematerial therein.

3. A gaseous electric discharge device comprising a container, a gaseousatmosphere therein comprising a metal vapor, electrodes sealed thereinone of which is a thermionic cathode and another oi. which is an anodehaving a large surface, electrode chambers for said electrodes, thechamber in which said anode is mounted having a larger diameter thansaid container, the chamber in which said cathode is mounted having asmaller diameter than said container, said anode being hollow, one wallthereof being perforated and a hollow tube projecting and opening intothe interior of said anode, said tube having a quantity of sodiumtherein.

HANS EWEST. ALFRED RUTI'ENAUER.

